At present, notepads have been more and more used in mobile terminal devices such as tablets or smartphones, and users can set a label for every note item. This kind of label can classify note items so that users can search all the note items with special labels recorded by himself or herself before through the labels.
However, notepad labels are realized by conventional text input in the prior art which may require multiple operating steps to reach the purpose of the demand, causing inconvenience to the user's operation. And from the viewpoint of protecting users' privacy, as the input text does not have personalized features, the privacy level is not high enough when identifying whether it is the user's own operation only by text, and it is easy to be guessed by others.
Therefore, it is urgent to find a method of searching note items which can help users search note items quickly and secretively.